Circuit Description
The electronic brake control module (EBCM) uses the lateral accelerometer signal to determine the lateral forces acting on a vehicle during a turn or a skid. The EBCM uses the signal from the lateral accelerometer as one of the inputs to operate the vehicle stability enhancement system (VSES).
DTC Descriptors
This diagnostic procedure supports the following DTC:
DTC C0186 Lateral Accelerometer Circuit
This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description .
DTC Symptom | DTC Symptom Descriptor |
|---|---|
00 | No Additional Information |
08 | Signal Invalid |
09 | Rate of Change Above Threshold |
19 | Signal Amplitude Above Maximum |
1A | Bias Level Out Of Range |
52 | Compare Failure |
Conditions for Running the DTC
C0186 00, 09, and 1A
| • | The ignition is ON. |
| • | Ignition voltage is greater than 8 volts. |
C0186 08
| • | Ignition voltage is ON. |
| • | Ignition voltage is greater than 8 volts. |
| • | The vehicle speed is greater than 0 km/h. |
C0186 19
| • | Ignition voltage is ON. |
| • | Ignition voltage is greater than 8 volts. |
| • | The vehicle is stationary. |
C0186 52
| • | Ignition voltage is ON. |
| • | Ignition voltage is greater than 8 volts. |
| • | DTC C0196 is not set. |
| • | The yaw rate is less than 8 degrees per second. |
Conditions for Setting the DTC
C0186 00, 09, and 1A
One of the following conditions exist:
| • | The lateral accelerometer sensor input voltage is less than 0.15 volt. |
| • | The lateral accelerometer sensor input voltage is greater than 4.85 volts for 0.03 second. |
C0186 08
The lateral accelerometer voltage does not increase at least 0.5 volt during the lateral accelerometer sensor self test.
C0186 09
The lateral jerk exceeds 11 g per second twice within 0.2 second.
C0186 19
The lateral acceleration is greater than 0.5 g for more than 1 second.
C0186 1A
Both of the following conditions exist:
| • | The compensated bias value of the lateral accelerometer sensor is greater than 0.3 g. |
| • | The yaw rate is centered. |
C0186 52
The slip rate error exceeds 0.5 g 60 times within one drive cycle.
Action Taken When the DTC Sets
If equipped, the following actions will occur:
| • | The EBCM disables the VSES for the duration of the ignition cycle. |
| • | The driver information center (DIC) displays the Service Stability System message. |
| • | The ABS/traction control system (TCS) remains functional. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and the DTC is cleared with a scan tool. |
| • | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
The lateral accelerometer is packaged with the yaw rate sensor as a single component.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for the proper voltage output on the 5-volt reference circuit and the proper operation of the signal circuit.
-
This step tests for possible low 5-volt reference output or a problem with the signal circuit.
-
This step tests for a short to voltage on the 5-volt reference circuit. If a short to voltage exists, other DTCs may be set for the vehicle stability system.
-
This step tests for a problem with the low reference circuit. If a short to voltage exists, other DTCs may be set for the vehicle stability system.
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | ||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||
Does the scan tool indicate that the lateral acceleration signal parameter is in between the specified voltage range? | 4.5-5.5 V | Go to Step 8 | Go to Step 3 | |||||||
With the 3-amp fused jumper wire still connected, does the scan tool indicate that the lateral acceleration sensor parameter is below the specified voltage value? | 4.5 V | Go to Step 5 | Go to Step 4 | |||||||
Test the 5-volt reference circuit of the yaw and lateral acceleration sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 7 | |||||||
5 | Test the 5-volt reference circuit of the yaw and lateral acceleration sensor for the following conditions:
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 6 | ||||||
6 | Test the lateral accelerometer signal circuit for the following conditions:
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 11 | ||||||
7 | Test the lateral accelerometer signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 11 | ||||||
Test the low reference circuit of the yaw and lateral acceleration sensor for the following conditions:
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 9 | |||||||
9 | Inspect for poor connections at the harness connector of the yaw and lateral acceleration sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 10 | ||||||
10 | Replace the yaw and lateral acceleration sensor. Refer to Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||
11 | Replace the electronic brake control module (EBCM). Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||
12 |
Does the DTC reset? | -- | Go to Step 2 | System OK | ||||||
